CN110138185B - Parallel current sharing control method for out-of-phase full-bridge converters of AC power supply device - Google Patents

Abstract

The invention discloses a parallel current sharing control method of an out-of-phase full-bridge converter of an AC power supply device, which comprises a feedback control circuit, a dead zone controller, a first full-bridge converter, and a second full-bridge A converter and a delay circuit, the output end of the dead zone controller is electrically connected to the input end of the first full-bridge converter, and the input end of the delay circuit is connected to the dead zone controller, the first full-bridge commutator The output terminal of the delay circuit is electrically connected to the input terminal of the second full-bridge converter, and the delay circuit receives a group of pulse width modulation signals. When the delay circuit receives the group of pulse width modulation signals changes, then according to a time delay control process, the group of PWM signals is adjusted to generate another group of PWM signals, so that the output voltages of the first full-bridge converter and the second full-bridge converter are The phases are staggered by 180 degrees and are consistent, so as to reduce the manufacturing cost and achieve the current sharing effect after parallel connection.

Description

Parallel current sharing control method for out-of-phase full-bridge inverters of AC power supply device

technical field

The present invention relates to an AC power supply device, in particular to a parallel current sharing control method of an out-of-phase full-bridge converter of the AC power supply device.

Background technique

The pulse modulation circuit in the traditional AC power supply device usually receives a set of input signals and a set of triangular carrier signals by an input circuit, the input circuit includes two identical amplifying circuits, and two amplifying circuits are connected through the two amplifying circuits. The dead zone controller is connected with two full-bridge converters to output two voltage signals at a time, but it has the problem of large output voltage distortion.

In the prior art, there is another interleaved pulse modulation circuit, which also receives a group of input signals and two groups of triangular carrier signals through an input circuit, and the input circuit also includes two identical amplifying circuits. One amplifier circuit connects two dead zone controllers, although the problem of distortion is reduced, but the problem of uneven current after parallel connection of two sets of full-bridge converters occurs.

According to the prior art, the pulse modulation circuit of the AC power supply device has the problems of output voltage distortion, uneven parallel current, and increased manufacturing cost, and it is necessary to propose more solutions.

SUMMARY OF THE INVENTION

In view of the above-mentioned problems of the prior art, the main purpose of the present invention is to provide a parallel current sharing control method for an out-of-phase full-bridge inverter of an AC power supply device, which is designed and improved for a pulse modulation circuit, which can reduce the manufacturing cost. cost and achieve the effect of current sharing after parallel connection.

The main technical means adopted to achieve the above-mentioned purpose is to make the staggered-phase full-bridge converters of the AC power supply device connected in parallel with the current sharing control method. A dead zone controller is connected to a first full-bridge converter, and a A delay circuit is connected between the dead zone controller and a second full-bridge converter, and the method mainly includes the following steps performed by the delay circuit:

receiving a first group of pulse width modulation signals;

According to a time delay control process, the first group of PWM signals is adjusted to generate a second group of PWM signals, the phase of which is 180 degrees different from the first group of PWM signals;

Through the same feedback control circuit, the output voltages of the first inverter and the second inverter are made the same, so that the paralleled currents are shared.

Preferably, the time delay control process includes a delay phase of 180 degrees.

According to the above method, the delay circuit receives the first group of PWM signals from the dead zone controller, and the delay circuit adjusts the first group of PWM signals according to the time delay control process to generate the second group of PWM signals The modulation signal, the phase of which is 180 degrees different from the first group of pulse width modulation signals, in order to achieve the effect of reducing the output ripple, thereby reducing the volume of the output filter and reducing the manufacturing cost; the same feedback control modulation circuit is used to make The output voltages of the first full-bridge inverter and the second full-bridge inverter are the same, so as to achieve the purpose of current sharing effect after parallel connection.

Another main technical means adopted to achieve the above-mentioned purpose is to make the above-mentioned AC power supply device include:

an input circuit with a signal output end;

a dead zone controller with a signal input end and two signal output ends, the signal input end of the dead zone controller is electrically connected to the signal output end of the input circuit;

a first full-bridge converter with two signal input ends and one signal output end, the two signal input ends of the first full-bridge converter are electrically connected with the two signal output ends of the dead zone controller;

a second full-bridge converter, having two signal input ends and a signal output end;

A delay circuit has two signal input ends and two signal output ends, the two signal input ends of the delay circuit are electrically connected between the dead zone controller and the first full-bridge converter, and the two signal output ends of the delay circuit is electrically connected to the two signal input ends of the second full-bridge converter;

The two signal input terminals of the delay circuit receive a first group of PWM signals, and adjust the first group of PWM signals with a time delay control to generate a second group of PWM signals. Its phase is 180 degrees different from the first group of PWM signals, and the delay circuit outputs the second group of PWM signals to the second full-bridge converter through two signal output terminals, so that the first full-bridge The output voltage and voltage phase of the inverter and the second full-bridge inverter are staggered by 180 degrees, and the output voltages of the first full-bridge inverter and the second full-bridge inverter are consistent, so that the parallel current Even flow.

Preferably, the input circuit further has more than one signal input terminal, and the signal input terminal of the input circuit is used for receiving a sinusoidal reference signal, a feedback signal, and generating a control signal according to a triangular carrier signal.

Preferably, the input circuit includes a feedback control circuit.

Preferably, the signal input terminal of the dead zone controller receives the control signal output by the input circuit, so that the dead zone controller outputs a first group of pulse width modulation signals.

Preferably, the first full-bridge converter generates a first output voltage signal according to a first group of pulse width modulation signals output by the dead zone controller; the delay circuit outputs a second group of pulse widths through two signal output terminals Modulate the signal to the second full-bridge inverter, so that a second output voltage signal generated by the second full-bridge inverter and the output voltage of the first full-bridge inverter are staggered by 180 degrees, which can reduce the output ripple, and reduce the volume of the output filter, and because the same feedback control circuit is used, the output voltages of the first full-bridge converter and the second full-bridge converter are consistent, so as to achieve parallel current sharing.

Preferably, the AC power supply device further comprises an output filter; the first full-bridge inverter and the second full-bridge inverter transmit the first output voltage signal and the second output voltage signal respectively to the output filter.

According to the above configuration, the delay circuit receives the first group of PWM signals from the dead zone controller, and the delay circuit adjusts the first group of PWM signals to generate the second group of PWM signals according to the time delay control process The modulation signal has a phase difference of 180 degrees with that of the first group of pulse width modulation signals, so that the output voltage phases of the first full-bridge converter and the second full-bridge converter are staggered by 180 degrees to achieve output ripple Reduced performance, thereby reducing the volume of the output filter, to achieve the purpose of reducing manufacturing costs, and because the same feedback control circuit is used, the output voltage of the first full-bridge inverter and the second full-bridge inverter are consistent, so as to achieve parallel connection The purpose of the post current sharing effect.

Description of drawings

The following drawings are only intended to illustrate and explain the present invention schematically, and do not limit the scope of the present invention. in,

1 is a block diagram of a circuit structure of a preferred embodiment of the present invention;

FIG. 2 is a schematic diagram of a parallel current sharing control method according to a preferred embodiment of the present invention.

Description of reference numbers:

10 input circuit 20 dead zone controller

30 The first full-bridge inverter 40 The second full-bridge inverter

50 delay circuit 60 output filter

Detailed ways

The technical means adopted by the present invention to achieve the predetermined purpose of the invention are further described below with reference to the accompanying drawings and the preferred embodiments of the present invention.

Regarding the preferred embodiment of the present invention, please refer to FIG. 1, which includes an input circuit 10, a dead zone controller 20, a first full-bridge inverter 30, a second full-bridge inverter 40, a The delay circuit 50 and an output filter 60; wherein, the input circuit 10 has more than one signal input end and a signal output end, the signal input end of the input circuit 10 is used for receiving a sinusoidal reference signal, a feedback signal, and A control signal is generated according to a triangular carrier signal; in this preferred embodiment, the input circuit includes a feedback control circuit; the dead zone controller 20 includes more than one inverter.

The dead zone controller 20 has a signal input terminal and two signal output terminals. The signal input terminal of the dead zone controller 20 is electrically connected to the signal output terminal of the input circuit 10 and receives the control signal output by the input circuit 10; A full-bridge inverter 30 has two signal input terminals and a signal output terminal. The two signal input terminals of the first full-bridge inverter 30 are electrically connected with the two signal output terminals of the dead zone controller 20 . The bridge converter 30 generates a first output voltage signal according to a first group of PWM signals output by the dead zone controller 20 .

The second full-bridge inverter 40 has two signal input terminals and a signal output terminal; the delay circuit 50 has two signal input terminals and two signal output terminals, and the two signal input terminals of the delay circuit 50 are electrically connected to the dead zone controller 20. Between the first full-bridge inverters 30, the two signal output terminals of the delay circuit 50 are electrically connected to the two signal input terminals of the second full-bridge inverter 40, and the two signal output terminals of the delay circuit 50 are electrically connected Receiving the first group of PWM signals output by the dead zone controller 20 and adjusting the first group of PWM signals with a time delay control, the delay circuit 50 outputs a second group of pulses through two signal output terminals Width modulate the signal to the second full-bridge inverter 40 so that a second output voltage signal generated by the second full-bridge inverter 40 and the first output voltage generated by the first full-bridge inverter 30 The signal phases are staggered by 180 degrees to achieve the effect of reducing the output ripple, thereby reducing the volume of the output filter and reducing the manufacturing cost. The output voltages of the bridge converters are the same, so as to achieve current sharing after parallel connection; finally, the first full-bridge converter 30 and the second full-bridge converter 40 respectively output the first output voltage signal and the second output voltage signal. The voltage signal is sent to the output filter 60 for filtering.

According to the structure of the above-mentioned preferred embodiment of the present invention, in this preferred embodiment, a parallel current sharing control method of an out-of-phase full-bridge inverter of an AC power supply device is further provided, which is mainly connected by the dead zone controller 20 . The first full-bridge inverter 30 and the delay circuit 50 are connected between the dead zone controller 20 and the second full-bridge inverter 40. Please refer to FIG. 2. The method is mainly performed by the delay circuit. 50 Perform the following steps:

receiving a first group of pulse width modulation signals output from the dead zone controller 20 (S51);

According to a time delay control process (S52), the first group of PWM signals is adjusted to generate a second group of PWM signals (S53); in this preferred embodiment, the time delay control process includes a Delay phase by 180 degrees;

Outputting the second group of PWM signals (S53), so that the output voltages of the second full-bridge inverter 40 and the first full-bridge inverter 30 are phase-staggered by 180 degrees, so as to reduce the output ripple and reduce the output filter volume to reduce manufacturing costs.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Personnel, within the scope of not departing from the technical solution of the present invention, can make some changes or modifications to equivalent examples of equivalent changes by using the technical content disclosed above. Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solutions of the present invention.

Claims (7)

1. A parallel current-sharing control method for an out-of-phase full-bridge inverter of an AC power supply device, characterized in that a first full-bridge inverter is connected by a dead zone controller and a first group of pulse width modulation is output. A signal is converted to the first full-bridge converter, and a delay circuit is connected between the dead zone controller and a second full-bridge converter. The method mainly includes the delay circuit performing the following steps: receiving the first group of PWM signals; A time delay control process, including a delay phase of 180 degrees; According to the time delay control process, the first group of PWM signals is adjusted to generate a second group of PWM signals, the phase of the second group of PWM signals and the first group of PWM signals are The phase difference is 180 degrees; The delay circuit outputs the second group of PWM signals to the second full-bridge inverter, so that the output voltage phases of the first full-bridge inverter and the second full-bridge inverter are staggered by 180 degrees; Through the same feedback control circuit, the output voltage of the first full-bridge inverter and the output voltage of the second full-bridge inverter are made the same, so that the paralleled currents are shared. 2. An AC power supply device, characterized in that the AC power supply device comprises: an input circuit with a signal output end; a dead zone controller with a signal input end and two signal output ends, the signal input end of the dead zone controller is electrically connected to the signal output end of the input circuit; A first full-bridge inverter has two signal input terminals and a signal output terminal. The two signal input terminals of the first full-bridge inverter are electrically connected with the two signal output terminals of the dead zone controller to receive the dead zone. a first group of pulse width modulation signals output by the controller; a second full-bridge converter, having two signal input ends and a signal output end; A delay circuit has two signal input ends and two signal output ends, the two signal input ends of the delay circuit are electrically connected between the dead zone controller and the first full-bridge converter, and the two signal output ends of the delay circuit is electrically connected to the two signal input ends of the second full-bridge converter; The two signal input ends of the delay circuit receive a first group of PWM signals, and adjust the first group of PWM signals with a time delay control to generate a second group of PWM signals, the The phase of the second group of PWM signals differs from that of the first group of PWM signals by 180 degrees, and the delay circuit outputs the second group of PWM signals to the second full bridge through two signal output terminals an inverter, so that the output voltage phases of the first full-bridge inverter and the second full-bridge inverter are staggered by 180 degrees, and the outputs of the first full-bridge inverter and the second full-bridge inverter The voltage is the same, so that the current after paralleling is shared; Through the same feedback control circuit, the output voltage of the first full-bridge inverter and the output voltage of the second full-bridge inverter are made the same, so that the paralleled currents are shared. 3 . The AC power supply device according to claim 2 , wherein the input circuit further has more than one signal input terminal, and the signal input terminal of the input circuit is used to receive a sinusoidal reference signal, a feedback signal, and A control signal is generated according to a triangular carrier signal. 4. The AC power supply device according to claim 2 or 3, wherein the input circuit comprises the feedback control circuit. 5 . The AC power supply device of claim 3 , wherein the signal input terminal of the dead zone controller receives the control signal output by the input circuit, so that the dead zone controller outputs the first group of pulse width modulation. 6 . Signal. 6 . The AC power supply device of claim 5 , wherein the first full-bridge inverter generates a first output voltage signal according to the first group of PWM signals output by the dead zone controller; 7 . The delay circuit outputs the second group of PWM signals to the second full-bridge inverter through two signal output terminals, so that a second output voltage signal generated by the second full-bridge inverter and the first full-bridge inverter The output voltage phase of the bridge converter is staggered by 180 degrees, which can reduce the output ripple and reduce the volume of the output filter, and because the same feedback control circuit is used, the first full-bridge converter and the second full-bridge converter are commutated. The output voltage of the device is the same to achieve parallel current sharing. 7 . The AC power supply device according to claim 6 , wherein the AC power supply device further comprises an output filter; the first full-bridge inverter and the second full-bridge inverter respectively The first output voltage signal and the second output voltage signal are sent to the output filter.

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